ZSA Motorsport

Im looking for a solution to minimize the decible level of a 2006 GT3 Cup and a 2010 GT3 Cup, (and while we're at it), a 2004 Boxster S with a fabspeed exhaust.

We were at Limerock today and ran into some decible level issues. Sucked having to lift intentionally to not get blacked flag for decibles.

When there, i saw a gt3 Cup (2004 i believe) with some curved exhaust tubing angled away from the side of th e track where they meter.
the mechanic who was prepping the car didnt know much abou tit, the owner wasnt around just yet. said "CX Racing on it". i called them, they had no idea and felt maybe soemone just used their stuff in that fashion but theyd didnt build stuff specifically for porsche..

anyway, any ideas?? thoughts??

Rassel

IIRC the decibel level on an -06 should be louder than a -10 if it's not running SuperCup exhaust.

Do you get trouble with both?

Sometimes decibel meters have trouble measuring if you put a simple down pointing device on the end tips. Not pretty, not optimal but could help and cheap.

(Note that they are pointed to the opposite direction of the measuring device, which in this case was set on the left side of the track.)

Bob Rouleau

spg - sounds like you are describing simple turn downs - no muffling inside they simply re-direct the sound towards the ground which reduces the sound pressure level at the meter. 2009 Cup cars use them on my home track. A simply piece of tubing which is firmly attached to the pipes. Looks lousy but they seem to work.

GT3 Techno

Here is a picture (sorry for the poor quality...) of the system described by Bob.

This is working very well with sound tested at 88db at full trottle on the track. Except that this is not only simple and plain tubing. There is some muffling inside plus there are also 2 others similar elbows between the headers and the muffler. Much better result than the pre-silencers sold by Porsche and at a fraction of the cost !

Bill Verburg

it's only going to get worse;

"The CT DMV regulation governing racetracks is being strictly enforced; cars made prior to January 1, 1979 are limited to 84 dB(A) moving and 78 dB(A) stationary. Cars made after January 1, 1979 are limited to 81 dB(A) moving and 74 dB(A) stationary. You will be black flagged for violating this, and after two black flags you will be excluded for the remainder of the day. Accordingly, please ensure your cars are as quiet as possible. And if you are black flagged once for noise, please make sure whatever modifications you make to your car are sufficient so you do not receive another."

93 FireHawk 968

I was at the Club Race in April and got black flagged despite having a car that sounds like a Lexus at idle. I was consistently north of 86 decibels despite using a turn down. I wonder how many cars will no longer go to LR with the strict enforcement of 84 decibels.

IPguy

Make certain to adequately muffle the intake as well, as it is can also be a source of significant noise as well, as per my prior experience with S14 M3s.